Reaction Times and Dyslexia

1994 ◽  
Vol 47 (1) ◽  
pp. 29-48 ◽  
Author(s):  
Roderick I. Nicolson ◽  
Angela J. Fawcett
Keyword(s):  
Pure Tone ◽  
Positive Response ◽  
Reaction Times ◽  
Chronological Age ◽  
Lexical Decisions ◽  
Choice Reaction Task ◽  
Two Factors ◽  
Pure Tones ◽  
Stimulus Classification ◽  
Reaction Task

Five groups of children, including two groups of dyslexics (aged 15 and 11 years), were tested on simple reaction, selective choice reaction, and lexical decision tasks. In simple reactions to a pure tone, the dyslexic children responded as quickly as their chronological age controls and significantly faster than their reading age controls. In selective choice reactions to pure tones, the dyslexic children were significantly impaired compared with their chronological age controls and no faster than their reading age controls. This speed impairment obtained even though a selective choice reaction task has only one positive response. In “by-item” analyses of lexical decisions to spoken words, the dyslexic children were significantly impaired compared even with their reading age controls. The pattern of results suggests that at least two factors contribute to slowness of dyslexic children: a general deficit reflected in slower stimulus classification speed and a linguistic deficit reflected in slower lexical access speed.

Heterogeneous auditory–visual integration: Effects of pitch, band-width and visual eccentricity

2012 ◽  
Vol 25 (0) ◽  
pp. 89
Author(s):  
Antonia Thelen ◽  
Micah M. Murray
Keyword(s):  
Pure Tone ◽  
Broad Band ◽  
Visual Stimuli ◽  
Reaction Times ◽  
Primary Auditory Cortex ◽  
Pink Noise ◽  
Preliminary Results ◽  
Low Level ◽  
Pure Tones ◽  
Gain Loss

The identification of monosynaptic connections between primary cortices in non-human primates has recently been complemented by observations of early-latency and low-level non-linear interactions in brain responses in humans as well as observations of facilitative effects of multisensory stimuli on behavior/performance in both humans and monkeys. While there is some evidence in favor of causal links between early–latency interactions within low-level cortices and behavioral facilitation, it remains unknown if such effects are subserved by direct anatomical connections between primary cortices. In non-human primates, the above monosynaptic projections from primary auditory cortex terminate within peripheral visual field representations within primary visual cortex, suggestive of there being a potential bias for the integration of eccentric visual stimuli and pure tone (vs. broad-band) sounds. To date, behavioral effects in humans (and monkeys) have been observed after presenting (para)foveal stimuli with any of a range of auditory stimuli from pure tones to noise bursts. The present study aimed to identify any heterogeneity in the integration of auditory–visual stimuli. To this end, we employed a 3 × 3 within subject design that varied the visual eccentricity of an annulus (2.5°, 5.7°, 8.9°) and auditory pitch (250, 1000, 4000 Hz) of multisensory stimuli while subjects completed a simple detection task. We also varied the auditory bandwidth (pure tone vs. pink noise) across blocks of trials that a subject completed. To ensure attention to both modalities, multisensory stimuli were equi-probable with both unisensory visual and unisensory auditory trials that themselves varied along the abovementioned dimensions. Median reaction times for each stimulus condition as well as the percentage gain/loss of each multisensory condition vs. the best constituent unisensory condition were measured. The preliminary results reveal that multisensory interactions (as measured from simple reaction times) are indeed heterogeneous across the tested dimensions and may provide a means for delimiting the anatomo-functional substrates of behaviorally-relevant early–latency neural response interactions. Interestingly, preliminary results suggest selective interactions for visual stimuli when presented with broadband stimuli but not when presented with pure tones. More precisely, centrally presented visual stimuli show the greatest index of multisensory facilitation when coupled to a high pitch tone embedded in pink noise, while visual stimuli presented at approximately 5.7° of visual angle show the greatest slowing of reaction times.

Effects of psychological pressure on motor cortex excitability and EMG activity in a choice reaction task

2011 ◽  
Vol 71 ◽  
pp. e242-e243
Author(s):  
Yoshifumi Tanaka ◽  
Kozo Funase ◽  
Hiroshi Sekiya ◽  
Joyo Sasaki ◽  
Yufu M. Tanaka
Keyword(s):  
Motor Cortex ◽  
Emg Activity ◽  
Choice Reaction Task ◽  
Motor Cortex Excitability ◽  
Psychological Pressure ◽  
Reaction Task

Use of Magnitude-Estimation Scaling for Predicting Hemispheric Processing of Lexical Decisions

1993 ◽  
Vol 76 (3_suppl) ◽  
pp. 1147-1152 ◽  
Author(s):  
Lee W. Ellis ◽  
Joan N. Kaderavek ◽  
Michael P. Rastatter
Keyword(s):  
Reaction Time ◽  
Lexical Decision ◽  
Analysis Of Variance ◽  
Magnitude Estimation ◽  
Reaction Times ◽  
Normal Subjects ◽  
Hemispheric Processing ◽  
Lexical Decisions ◽  
Significant Magnitude ◽  
Abstract Words

The purpose of this study was to evaluate the usefulness and validity of magnitude-estimation scaling as an alternative to a traditional, somewhat more cumbersome reaction-time procedure in the assessment of hemispheric processing asymmetry. Lexical decision vocal reaction times and magnitude-estimation scaling values were obtained for 16 normal subjects to tachistoscopically presented concrete and abstract words. Analysis of variance showed identical interactions of field x stimuli for each dependent variable while all pair-wise correlations between these measures were significant. Magnitude-estimation scaling may be a sensitive measure of visual psychophysical differences in hemispheric processing and may circumvent problems with variance of latencies associated with disordered populations.

The Effects of Midazolam on Pure Tone Audiometry, Speech Audiometry, and Audiological Reaction Times in Human Volunteers

1999 ◽  
Vol 88 (5) ◽  
pp. 1064-1068 ◽  
Author(s):  
Dermot J. Kelly ◽  
Fergus Walsh ◽  
Gary S. Norman ◽  
Anthony J. Cunningham
Keyword(s):  
Pure Tone ◽  
Reaction Times ◽  
Pure Tone Audiometry ◽  
Speech Audiometry ◽  
Human Volunteers

Effects of Cigarette Smoking on Lexical Decision-Making

1999 ◽  
Vol 84 (1) ◽  
pp. 117-120 ◽  
Author(s):  
Christina R. Hale ◽  
Mark V. Gentry ◽  
Charles J. Meliska
Keyword(s):  
Decision Making ◽  
Cigarette Smoking ◽  
Lexical Decision ◽  
Memory Retrieval ◽  
Reaction Times ◽  
Smoking Abstinence ◽  
Response Accuracy ◽  
Lexical Decisions ◽  
Nicotine Delivery

10 habitual smokers, aged 19–25 yr., were randomly assigned to smoke either a very low nicotine “Placebo” cigarette (.05-mg nicotine delivery as estimated by the FTC method) or a Nicotine cigarette (.7-mg estimated nicotine delivery). Each participant was asked to abstain from smoking for 4 to 7 hr. prior to testing. After completing a presmoking test of lexical decision-making, participants smoked either a Nicotine or Placebo cigarette and were then retested for reaction times and accuracy on the lexical decision test. When presented the most difficult lexical decisions, participants responded significantly faster after smoking a Nicotine cigarette than they did before smoking; smoking a Placebo cigarette did not affect reaction times. Response accuracy was unaffected by smoking either kind of cigarette. These results suggest that smoking a nicotine cigarette may improve attention or memory retrieval after several hours of smoking abstinence.

Spread-of-Masking Effects on Pure Tones and Several Speech Stimuli

1973 ◽  
Vol 16 (3) ◽  
pp. 385-396
Author(s):  
Richard H. Wilson ◽  
Richard W. Stream ◽  
Donald D. Dirks
Keyword(s):  
Pure Tone ◽  
Narrow Band ◽  
Wide Band ◽  
Intensity Level ◽  
Speech Stimuli ◽  
Intensity Range ◽  
Speech Spectrum ◽  
Series Of Experiments ◽  
Pure Tones ◽  
Upper Slope

A series of experiments was performed to study the upward-spread-of-masking phenomena as it pertains to pure-tone and speech stimuli. In the initial two experiments, three maskers were employed over a 40–60-dB intensity range. They included a wide band (50–5500 Hz), a speech spectrum (50–1000 Hz), and a narrow-band (50–950 Hz) noise. All filter slopes were 48 dB/octave, except for the upper slope of the speech-spectrum noise that was 6 dB/octave. In the first experiment, pure-tone thresholds obtained by a tracking procedure revealed no spread of masking when the wide-band and speech-spectrum maskers were used. Substantial spread-of-masking effects, characterized by nonlinear threshold increments outside the spectrum of the masker, were observed with the narrow-band masker. The second experiment included three types of speech stimuli (PBs, spondees, and synthetic sentences) under the same mask conditions used with the pure tones. Threshold shifts observed for the wide- and speech-spectrum maskers were linear with the masking intensity level. However, increased shifts, attributable to spread of masking, were observed with the narrow band and progressed nonlinearly as a function of the masking level. Finally, two additional experiments, performed with two different narrow-band maskers and spondee words, provided insightful information regarding the effects of the spread of masking on speech stimuli.

Measurements of Multiple Pure Tone Propagation From a High Bypass Turbofan Rotor in an Internal Flow Facility

2020 ◽  
Author(s):  
Richard F. Bozak
Keyword(s):  
Pure Tone ◽  
Dynamic Pressure ◽  
Pressure Ratio ◽  
Internal Flow ◽  
Principal Component ◽  
Pressure Transducers ◽  
Acoustic Liners ◽  
Pure Tones ◽  
Dynamic Pressure Measurements ◽  
Stagger Angle

Abstract An important noise source in modern high bypass ratio turbofans is from multiple pure tones produced by the fan during takeoff. An experiment conducted on a 1.5 pressure ratio fan in an internal flow facility provided dynamic pressure measurements to investigate multiple pure tone generation and propagation. Since multiple pure tones are generated by blade shock variation primarily due to the fan’s blade stagger angle differences, the blade stagger angles were measured with an array of over-the-rotor dynamic pressure transducers. Multiple pure tone measurements were made with 30 wall-mounted dynamic pressure transducers from 0.4 to 1.1 diameters upstream of the rotor. Measured blade stagger angle differences correspond to the the shock amplitude variation measured upstream. The acoustic field was extracted from the dynamic pressure signals using principal component analysis as well as duct mode beamforming. Shocks traveling out the inlet were found to couple to duct modes propagating at similar angles. Over-the-rotor acoustic liners appear to reduce rotor shock variation resulting in a reduction of sub-harmonic multiple pure tone sound pressure levels by 3–4 dB.

Fatigue effects of a pure tone and pure tones

1989 ◽  
Vol 86 (S1) ◽  
pp. S121-S121
Author(s):  
I. M. Young ◽  
L. D. Lowry
Keyword(s):  
Pure Tone ◽  
Pure Tones

Responses To Songs With Altered Tonal Quality By Adult Song Sparrows (Melospiza Melodia)

Behaviour ◽  
1996 ◽  
Vol 133 (3-4) ◽  
pp. 161-172 ◽  
Author(s):  
Stephen Nowicki ◽  
Jared Strote
Keyword(s):  
Adult Male ◽  
Distinctive Feature ◽  
Pure Tone ◽  
Playback Experiments ◽  
Perceptual Salience ◽  
Song Recognition ◽  
Song Sparrows ◽  
Sensitive Phase ◽  
Pure Tones

AbstractPure-tone sounds are a common and distinctive feature of many birdsongs. We used field playback experiments to test whether this tonal quality is perceptually salient to adult male song sparrows in the context of song recognition, by comparing responses to playback of normal songs with responses elicited by songs that had harmonics added. This species was chosen for study based on the recent finding that young song sparrows do not show a preference for songs with pure tones over songs with harmonics when choosing model songs to copy during their sensitive phase for learning. We found adult song sparrows to be significantly more responsive to normal song than to harmonic song, consistent with results from adult birds of other species. We conclude that the perceptual salience of the tonal quality of song changes during ontogeny or is context-dependent.

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